I'd prefer people get offended. That company has a decent nonzero chance of raising its future offers.
Your initial offer as a company signals a lot of things aside from the raw value. Even a $10000 improvement in starting point may signal "we won't cheapskate you on:"
- personal computing equipment
- infrastructure
- benefits
- actual use of vacation
- training/development
- office/cube/chair
- functioning HR/support systems
- proper staffing
Let's not pretend there is perfect information on companies. All large companies have good and bad teams. I wouldn't bother with Amazon because landing a "good" amazon team lottery ticket attempt is not worth the interviewing time, stack ranking, hostile culture, and "new job vulnerability" etc that Amazon imposes.
It's why the best IT jobs are found via networking, and the best candidates don't really hit the open market.
So HR opening with an insulting offer is very likely ruining a far better hire/fit than an open market negotiation. Typically HR does not distinguish between the two. They should. Of course it can be hard to distinguish between a "good hire" via recommendation and someone building an organization of lackeys, but that is also something HR needs to evaluate, and not simply revert to "cheap offer for everyone".
It is very important to emphasize how vulnerable you are switching jobs. Unless your skillset VERY CLOSELY matches the new job (and that is pretty rare), you won't know their codebase, processes, political/budgeting/power structure, business requirements.
Depending on the company, they'll either have good onboarding and tolerance, or... sink or swim. And people fundamentally don't like helping new hires outside of whatever perverse virtue signalling they want to show to their bosses. Every company's HR and Ticket systems are byzantine and annoying, and helping new hires through that is basically reliving the torturous new hire process for whomever helps them.
A cheap offer also shows that they will pull the plug on your quickly. A good offer is a willing sign of investment. All those common fallacies in human nature with sunk cost / valuing things what they cost you / etc are very very very much things in a human organization.